Hyperarousal is a key symptom of PTSD. Even after receiving trauma-focused therapy, PTSD patients may continue to suffer from hyperarousal. Neuroimaging findings in PTSD support the idea that regulation of autonomic arousal from the cingulate cortex can be helpful in reducing anxiety. Our main objectives are to measure hyperarousal in VA outpatients with PTSD related to combat experience in the last 10 years and to test the efficacy of physiological relaxation training in reducing this hyperarousal. Measurements will be both physiological, using 24 hour ambulatory monitoring of skin conductance, heart rate, and physical activity during waking and sleeping, and psychological, using self-reports and clinician interviews. Specific aims include initially evaluating 100 or more PTSD patients for the severity of their hyperarousal symptoms. Of these, 50 with at least moderate hyperarousal who either have participated in a trauma-focused therapy or have declined to participate in such a therapy will be recruited for a therapy trial. Volunteers will be randomized to treatment consisting of 5 sessions of individual physiological relaxation training with electromyographic and capnographic feedback over a 4-week period or to a 2-month waiting period after which they also may receive this therapy. Physiological evaluations of the patients'ability to relax while sitting quietly and their arousal levels during daily activities and sleep will be measured at three times - before treatment, 1 month after treatment, and 6 months after treatment. Clinical evaluations by interviews and questionnaires on measures of symptoms and disability will be measured at the same time points. The waiting-list group and a nonanxious control group will be tested psychophysiologically twice at the same interval as the patients before and 1 month after treatment. The control group will allow us to calibrate our physiological measures in the setting in which they are being applied. We hypothesize that this therapy will relieve both self-reported and objective, physiological symptoms of hyperarousal. Relevance to health and the VA mission: Many of our clients at the VA Palo Alto Mental Health Outpatient Services for PTSD are veterans of Iraq who need help with hyperarousal symptoms. This study will fill in gaps in our knowledge about the physiology of these symptoms and about the efficacy of relaxation therapies. Non- pharmacological treatments like the ones that we propose may relieve patients'hyperarousal to an extent that they are less tempted to turn to alcohol or sedative drugs. Physiological proof of the effectiveness of relaxation procedures in this clinical group would help convince clinicians to apply them and patient consumers to try them. PUBLIC HEALTH RELEVANCE: This project is highly relevant because of the large number of soldiers returning from Iraq are likely to be diagnosed with a mental illness, and about half of those will receive a diagnosis of PTSD. We mental health professionals and researchers are making every effort to prepare us for their treatment. Supplemental non- pharmaceutical treatments for hyperarousal need to be tested for efficacy in this new wave of PTSD patients, to establish their role among other treatments that are being offered or will be offered. VA mental health personnel know from past experience that combat PTSD patients often do not respond to a single treatment or treatment program. Having more treatment options with proven efficacy, will be of great clinical utility. Attempts to relieve anxiety with alcohol or other substances may be the reason for the high comorbidity between PTSD and alcohol and substance abuse in US combat veterans, although in some studies, substance abuse has tended to precede the traumatic event [13]. Ways for veterans to control their anxiety without the use of alcohol or benzodiazepine anxiolytics, which also tend to be problematic in this population, could be of great value in relieving the distress and disability caused by PTSD. In fact, non-drug anxiety management techniques have often been included in therapy packages for PTSD, but until a package is "dismantled," the current and future value of its individual components cannot be known. Although it is unlikely that any relaxation method can replace other therapy components known to be useful in PTSD such as exposure and cognitive restructuring, the methods we propose could turn out to be important supplements to those therapies. This application is innovative in being willing to challenge two clinical objections that have discouraged acceptance of relaxation for treatment of PTSD and other anxiety disorders: First, that relaxation is a "safety aid," ultimately limiting treatment success, and second, that a treatment directed to a single symptom of PTSD rather than to the disorder as a whole cannot be useful. Efficacy trials that we conducted have shown that such objections are not valid for PD and trials in progress suggest that they are not valid for episodic anxiety, a kind of spectrum PD, or for PTSD symptoms in those patients. Furthermore, we challenge the assumption that trauma-focused therapies make SMT irrelevant since they address the specific causes of PTSD. Our experience with persistent hyperarousal and other PTSD symptoms in veterans of previous wars gainsays this. Finally, in assessing our results we will examine physiological measures of relaxation, not just self- report and clinical measures. Physiological monitoring will be applied not only during the training exercises and in the laboratory, but also ambulatorily for 24-hour periods that include daily activities and sleep.